Daughter gets sheep drink (4)
I believe the answer is:
dram
'drink' is the definition.
(small alcoholic drink)
'daughter gets sheep' is the wordplay.
'daughter' becomes 'd' (genealogical abbreviation).
'gets' means one lot of letters go next to another.
'sheep' becomes 'ram' (male sheep).
'd'+'ram'='DRAM'
(Other definitions for dram that I've seen before include "Apothecary's weight, 60 grains" , "A wee spirit" , "Small drink of alcohol" , "Measure of spirits" , "Wee drop of whisky?" .)